From 6a28b5c9908d6e7ea13eae7a5872e8e081a397c4 Mon Sep 17 00:00:00 2001 From: Baokun Li Date: Fri, 21 Nov 2025 17:06:37 +0800 Subject: [PATCH] ext4: support large block size in ext4_calculate_overhead() ext4_calculate_overhead() used a single page for its bitmap buffer, which worked fine when PAGE_SIZE >= block size. However, with block size greater than page size (BS > PS) support, the bitmap can exceed a single page. To address this, we now use kvmalloc() to allocate memory of the filesystem block size, to properly support BS > PS. Suggested-by: Jan Kara Signed-off-by: Baokun Li Reviewed-by: Zhang Yi Reviewed-by: Jan Kara Reviewed-by: Ojaswin Mujoo Message-ID: <20251121090654.631996-8-libaokun@huaweicloud.com> Signed-off-by: Theodore Ts'o --- fs/ext4/super.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 2286cd1e3cb83..998ddce490931 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -4191,7 +4191,7 @@ int ext4_calculate_overhead(struct super_block *sb) unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum); ext4_group_t i, ngroups = ext4_get_groups_count(sb); ext4_fsblk_t overhead = 0; - char *buf = (char *) get_zeroed_page(GFP_NOFS); + char *buf = kvmalloc(sb->s_blocksize, GFP_NOFS | __GFP_ZERO); if (!buf) return -ENOMEM; @@ -4216,7 +4216,7 @@ int ext4_calculate_overhead(struct super_block *sb) blks = count_overhead(sb, i, buf); overhead += blks; if (blks) - memset(buf, 0, PAGE_SIZE); + memset(buf, 0, sb->s_blocksize); cond_resched(); } @@ -4239,7 +4239,7 @@ int ext4_calculate_overhead(struct super_block *sb) } sbi->s_overhead = overhead; smp_wmb(); - free_page((unsigned long) buf); + kvfree(buf); return 0; } -- 2.47.3